This application is based upon and claims the benefit of priority from the prior Japanese Patent Applications No. 2002-208817, filed Jul. 17, 2002; No. 2002-208818, filed Jul. 17, 2002; and No. 2003-172608, filed Jun. 17, 2003, the entire contents of all of which are incorporated herein by reference.
1. Field of the Invention
The present invention relates to a color photosensitive material. Particularly, the present invention relates to a color photosensitive material, especially a color negative film for still photography, which is suitable for photographing in cloudy weather or of night scenes.
2. Description of the Related Art
In recent years, the use of zooming in compact cameras is being advanced. It is now the main current to use high zooming units enabling zooming to a magnification of 3 or 4. Such zooming units are useful for light heartedly enjoying of photographing, but the current situation is that the image quality is not always satisfactory. For example, there are units whose lens F-value exceeds 10 on its telescopic side, which are likely to cause under-exposure. Further, there often occur units whose electronic flash range is so short that the flash light cannot reach an intended location to thereby cause under-exposure.
Advanced Photo System (hereinafter simply referred to as xe2x80x9cAPSxe2x80x9d) whose image size was smaller than that of the conventional 135-format was put on sale in 1996. Taking advantage of the smaller format, miniaturization of camera is being promoted. There are units whose electronic flash has been miniaturized in accordance with the camera miniaturization. With respect to the APS, the ratio of failure photograph caused by non-reaching of electronic flash light tends to increase.
An ordinary photographer who uses a compact type camera or a single-use camera usually photographs a subject in a dim scene by use of auxiliary light like a flashlight. Photography with the flashlight, however, has the following problems:
(1) flashlight photography is prohibited or not acceptable in a quiet and calm situation;
(2) flashlight tends to cause red-eye effect, especially in photography with the compact type camera;
(3) flashlight photography causes an unnatural print picture because of too high contrast;
(4) flashlight tends to make unusual shadows of a main subject in front of a wall;
(5) if the color temperatures of the flashlight and the background light are largely different, a print picture tends to have color failure due to mixed light of the flashlight and the background light;
(6) a photo film is exposed to the unexpected flashlight reflected on a glass, a window, a mirror or the like, which are located in a photographed area; and
(7) flashlight photography causes a dark background if the amount of the flashlight is not controlled properly.
A skillful photographer is able to deal with the above problems by use of special photography equipments. For instance, multiple flashlight sources are able to solve the problem (4) above. It is possible to solve the problem (5) by attaching a color conversion filter or a light balancing filter, which is adapted to the color temperature of the background light, to the flashlight emission window. In addition, bounced flashlight is utilized to solve the problem (6) above.
However, it is difficult to solve the above problems for an ordinary photographer who usually uses a compact type camera or a single-use camera. Moreover, flashlight photography is impossible in the situation where the supplementary light is prohibited or not acceptable because of ill-manner.
In order to solve these problems it is desirable to have a satisfactory print picture without the flashlight and any special operation by an ordinary photographer. Without the flashlight, however, many cameras will cause under exposure of main subjects. Moreover, an ordinary photographer finds it difficult to obtain a satisfactory print picture of a low color temperature scene, because a color correction process in printing operation can not correct the color temperature properly.
In recent years, highly sensitive photosensitive materials are placed on market in succession in accordance with the progress of the technology of photosensitive materials for photographing. Highly sensitive films are xe2x80x9cusable in photographing in dark scenesxe2x80x9d, so that the frequency of use thereof in dark indoor places is increasing. On the other hand, especially in Japan, fluorescent lamps are very often installed as indoor illuminants, and scenes illuminated by fluorescent lamps are printed greenish. The higher the speed of the film, the greater the influence of the background light source on the film. Accordingly, the occurrence of greenish printing attributed to fluorescent lamps is greater with ISO-400 films than with ISO-100 films and greater with ISO-800 films than with ISO-400 films. Fuji Photo Film Co., Ltd. have developed color negative film xe2x80x9cSuperia X-tra 800xe2x80x9d realizing a color reproduction that is faithful to human sight, thereby having improved the light source compatibility with respect to ISO-800 film. This color negative film, although having succeeded in conspicuously reducing the failure caused by non-reaching of electronic flash light and the defect of color tint attributed to fluorescent lamps, often encounters feeling of poor speed in cloudy weather.
Further speed increase is demanded for coping with these failures. However, further speed increase is likely to suffer side effects such as deterioration of graininess and hence may not be favorable from the viewpoint of versatility.
Moreover, improvement of graininess is likely to lead to an increase of coating silver quantity and an increase of film thickness, which are unfavorable from the viewpoint of realization of rapid development processing and replenishment reduction for processing solutions.
The object of the present invention is to provide a silver halide color photosensitive material, especially a color negative film for still photography, which is free from under-exposure even in the use in compact cameras and single-use cameras which enables obtaining excellent photographs over a wide exposure range, and which ensures excellent rapid processability.
Another object of the present invention is to provide a silver halide color photosensitive material, especially a color negative film for still photography, which enables obtaining excellent photographs over a wide exposure range without causing under-exposure, even in photographing a dim scene, such as in indoor or night photography, by use of compact cameras or single-use cameras without auxiliary light.
The inventors have found, as a result of extensive and intensive efforts, that the object of the present invention can be attained by the following means.
(1) A silver halide color photosensitive material comprising at least one red-sensitive silver halide emulsion layer, at least one green-sensitive silver halide emulsion layer and at least one blue-sensitive silver halide emulsion layer, on a support, wherein the silver halide color photosensitive material has ISO speed of 1000 or higher, and has the ISO speed of 1.25 times an indicated speed or higher.
(2) The silver halide color photosensitive material according to item (1) mentioned above, wherein the ISO speed is 1250 or higher and 2.8 times the indicated speed or higher
(3) The silver halide color photosensitive material according to item (1) or (2) mentioned above, wherein the following formula is satisfied;
log10HBxe2x88x92log10HGxe2x89xa6xe2x88x920.20
wherein HB, HG are exposure amounts corresponding to the points whose diffuse densities are (minimum density+0.15) in characteristic curves for blue and green;
wherein the characteristic curves for blue and green are obtained by gray exposure for {fraction (1/100)} sec to an emulsion side surface by use of an ISO daylight illuminant under the condition regulated by ISO 5800, by measuring blue and green diffuse density (ISO status M) after development.
(4) The silver halide color photosensitive material according to any one of items (1) to (3) mentioned above, wherein each of the red-sensitive silver halide emulsion layer, the green-sensitive silver halide emulsion layer and the blue-sensitive silver halide emulsion layer is composed of at least two layers having different speeds comprising a highest speed and a lowest speed, and at least one of the layers having the highest speeds do not substantially contain a DIR compound capable of releasing a development inhibitor and/or a precursor of a development inhibitor.
(5) The silver halide color photosensitive material according to any one of items (1) to (4) mentioned above, wherein the photosensitive material contains a compound capable of undergoing a one-electron oxidation to thereby form a one-electron oxidation product thereof, wherein the one-electron oxidation product is capable of releasing further one or more electrons.
(6) The silver halide color photosensitive material according to any one of items (1) to (5) mentioned above, wherein the green-sensitive silver halide emulsion layer has a weight-averaged wavelength (xcexG) of spectral sensitivity distribution satisfying the relationship 520 nm less than xcexGxe2x89xa6580 nm, and wherein the red-sensitive silver halide emulsion layer has a weight-averaged wavelength (xcexxe2x88x92R) of spectral sensitivity distribution of magnitude of interlayer effect exerted thereupon, in the range of 500 nm to 600 nm, by other silver halide emulsion layers satisfying the relationship 500 nm less than xcexxe2x88x92Rxe2x89xa6560 nm, and wherein xcexGxe2x88x92xcexxe2x88x92R is 5 nm or greater.
(7) The silver halide color photosensitive material according to any one of items (1) to (6) mentioned above, wherein the silver halide color photosensitive material is a color negative film for still photography.
(8) A photographic product into which the silver halide color photosensitive material according to any one of (1) to (7) mentioned above is built, and which comprises an exposure mechanism including a photographic lens and a shutter.